The suspect in a deadly Staten Island home invasion is undergoing a psychiatric evaluation at Bellevue Hospital Tuesday after police say he fatally stabbed 67-year-old Peter Gialluisi.

Gialluisi's wife was stabbed in the neck and back and remains in the hospital.

Twenty-year-old Dante Viggiano has been charged with murder, attempted murder, burglary, criminal mischief, possession of a weapon and false impersonation in connection with the vicious home invasion that rattled the Woodrow neighborhood, where crimes of this nature rarely happen.

Authorities say 66-year-old Vincenza Gialluisi fought to protect her disabled husband from the knife attack in their home on Venus Place. She then ran screaming to a neighbor for help.

Peter had difficulty walking and needed a walker to get around.

The couple had surprised the intruder when they returned from a birthday party in New Jersey.